diff --git a/lsyncd.h b/lsyncd.h
index 9300a09..1961a5c 100644
--- a/lsyncd.h
+++ b/lsyncd.h
@@ -13,6 +13,7 @@
 
 // some older machines need this to see pselect
 #define _DEFAULT_SOURCE 1
+#define _BSD_SOURCE 1
 #define _XOPEN_SOURCE 700
 #define _DARWIN_C_SOURCE 1